Collect, edit, store, and analyze data as described in the manual of operations of the Coronary Artery Surgery Study. Coordinate yearly telephone contact with surviving randomized and randomizable CASS patients. Interrogate the National Death Index on a yearly basis concerning deaths of registry patients and retrieve death certificates from the appropriate state agency when a death occurs. Accumulate and maintain appropriate confidential and secure data files. Coordinate and support travel of CASS investigators of data analysis and administrative meetings. Participate actively with other CASS investigators in data analysis and administrative meetings. Subject to scientific priorities (as directed by the Project Officer) and mutually acceptable arrangements with the VA and European investigators, collaborate in joint analysis of the VA, CASS, and European trials of coronary artery bypass surgery.